The present invention relates generally to a cable hanger and, more particularly, to a cable hanger including a flexible metallic strip, with the metallic strip having attachment legs formed at opposite ends thereof for being inserted into an installation opening of a support structure, and a medial portion between the attachment legs for releasably holding a section of cable.
It is well known to use cable hangers of the above-described type to secure cables to towers. More specifically and for each cable and tower, multiple cable hangers hold the cable and are removably mounted to the tower at positions that are spaced apart along the height of the tower. It is typical for the towers to be of considerable height. Because of safety considerations as well as the time and expense involved with installing cables to towers, it is advantageous to minimize both the amount of time and the complexity of the work required for running cables up the towers. Consequently, cable hangers that can be used to easily and rapidly attach cables to towers and other types of support structures without the need for conventional hardware, such as bolts, washers, nuts or other small parts, have been developed. Examples of these cable hangers are disclosed in U.S. Pat. Nos. 4,763,132; 4,813,639; 5,393,021 and 5,967,468.
A problem with some cable hangers of the above-described type is that they do not strike an optimal balance between performance characteristics. For example, some that are capable of being sufficiently securely mounted to a support structure and capable of sufficiently securely gripping a cable are relatively difficult to install by hand.
Another problem stems from the fact that it is common for the size of installation openings of support structures and the diameters and cross-sectional shapes of cables to vary. Some cable hangers of the above-described type are disadvantageously very sensitive to these variations. For example, some cable hangers can be very difficult to install or uninstall when used with oversized or misshaped cables, and the ability of some cable hangers to hold a cable diminishes considerably when used with slightly undersized or misshaped cables.
Accordingly, there is a need for a cable hanger that can be easily attached to a support structure manually, and which will securely grip and retain a cable in position on a support structure.
Additionally, there is a need for a cable hanger having an enhanced tolerance for variations in cable size or variations in the installation openings.
In accordance with one aspect of the present invention, a cable hanger is provided which includes a flexible resilient strip. The strip preferably has attachment legs formed at opposite ends thereof configured for being inserted into an installation opening on a support structure. The strip also has a medial portion between the attachment legs and shaped to form a cable holding section defining a longitudinally extending passageway for receiving and at least partially surrounding the cable. The cable holding section includes a slot extending at least partially around the circumferential extent of the passageway. The slot defines a torsion spring in the cable holding section. The torsion spring extends along at least one side of the slot and at least partially around the passageway. The slot preferably extends around at least about one-half the circumferential extent of the passageway. At least one gripping projection projects from the torsion spring and is oriented for grippingly engaging the surface of a cable placed in the passageway so that the torsion spring is torsionally deflected. The gripping projection is preferably a cantilevered gripping tab that projects laterally into the slot.
In accordance with another aspect of the present invention, an additional slot is formed in the cable holding section and extends at least partially around the circumferential extent of the passageway. The additional slot defines an additional torsion spring in the cable holding section. The additional torsion spring extends at least partially around the passageway and is capable of torsional deflection. At least one gripping projection, which is preferably a gripping tab, projects from the additional torsion spring and is oriented for grippingly engaging the surface of a cable placed in the passageway so that the additional torsion spring is torsionally deflected.
In accordance with a further aspect of the present invention, each gripping tab includes a gripping protrusion formed therein and facing inwardly toward the passageway for gripping the surface of a cable. Preferably at least one additional gripping protrusion is formed on the cable holding section at a location spaced from the gripping tabs for gripping another portion of the surface of the cable.
Also in accordance with an aspect of the present invention, the cable holding section includes a first circumferentially extending slot formed in the cable holding section and extending at least partially around the circumferential extent of the passageway, and a pair of second circumferentially extending slots formed in the cable holding section on opposite sides of the first slot. The first slot and the pair of second slots define in the cable holding section along opposite sides of the first slot a pair of torsion springs extending at least partially around the passageway and capable of torsional deflection. For each torsion spring, at least one gripping projection projects from the torsion spring and is oriented for grippingly engaging the surface of a cable placed in the longitudinal passageway.
In accordance with one aspect of the present invention, the first slot is of substantially uniform width along its extent, and each of the second slots include respective reduced width portions defining the gripping projections so that they are in the form of cantilevered gripping tabs. Each gripping tab preferably includes a gripping protrusion formed therein and facing inwardly toward the passageway for gripping the surface of a cable.
In accordance with one aspect of the present invention, the cable holding section further includes a pair of bands adjacent the second slots. The bands extend circumferentially at least partially around the passageway.